Work or goals proposed for the second year of the grant period are directed toward the following: 1) Techniques for separation of glia and neuronal nuclei from mammalian brain will be developed. The technique to be utilized is elutriation-centrifugation. 2) Nuclear RNA from neuronal and glial nuclei will be compared by DNA/RNA hybridization. This comparison should permit a conclusion as to whether extensive complexity of genetic transcription (previously reported) is a property of neurons or glial, or both. 3) Transcriptional overlap will be examined between various regions of the cerebrum and between cerebrum and cerebellum. Current data indicates the extensive overlap exists; therefore evidence for regionally unique transcripts (RNA molecules) will be sought. 4) Studies on model systems designed to examine empirically the resolution of DNA/RNA hybridization will be continued. 5) DNA/RNA hybridization studies utilizing "poly-A"-RNA and mRNA derived from polysomes will be initiated to determine the portion of unique sequence transcripts which function as messenger RNA in the mammalian brain.